Four Iraqi national guards have been killed and at least 80 injured in a major attack on their headquarters north of the capital, Baghdad.
Smoke was seen rising from the scene of the blast
Iraqi officials and the US military said insurgents fired several mortar rounds at the building in Mushahida, 40km (25 miles) from the Iraqi capital.
US helicopters helped ferry the injured to two military field hospitals.
Iraq's fledgling security forces are a frequent target for militants opposed to the US-backed government.
"A national guard base was attacked this morning, four people
were killed and 80 wounded, all of them national guards," a defence ministry official told the AFP news agency.
An American military spokeswoman said no US soldiers had been hurt.
IRAQI NATIONAL GUARD
40,000-strong paramilitary unit
Operates under command of US-led forces
in conjunction with Iraqi national security and defence ministries
Formed in Sep 2003 by US-led authorities
The attack comes less than a week after bombs killed five people in Baghdad's heavily fortified Green Zone and is the latest to target the security forces.
Since the start of the Muslim holy month of Ramadan last week, 13 police officers have been killed in separate incidents.
In other developments:
- A senior aid worker was kidnapped in Baghdad
Two Iraqis were killed and three were injured when three car bombs exploded in the northern city of Mosul, the Associated Press news agency reported
- A US contractor was killed and several people were wounded in a mortar attack on a US army compound in central Baghdad, the US military said
- A key oil pipeline in northern Iraq was attacked and set on fire
- More than 100 suspected insurgents were arrested by Iraqi security forces, backed by US Marines, in raids in Babil province, south of Baghdad
- A suicide car bomber attacked a US military convoy in the western town of
Habbaniyah, police told the Reuters news agency. There were no reports of casualties